1. Field of the Invention
The present invention relates to an air filtering apparatus for supplying power from a power supply to electrodes in an electrolytic bath to electrolyze water in the electrolytic bath and thus generate electrolytic water, and removing microorganisms floating in the air such as bacteria, virus, fungus, etc. (hereinafter merely referred to as “virus, etc.”) by using the electrolytic water.
2. Description of the Related Art
There is known a humidifying element for supplying power from a power supply to electrodes in an electrolytic bath to electrolyze water in the electrolytic bath and thus generate electrolytic water containing hypochlorous acid and subjecting sterile filtration to a humidifying element by using the electrolytic water (for example, see JP-A-2002-181358). In this apparatus, a power supply having a power supply switch (using DC 12V to 18V) is connected to the electrodes and the power supply switch is turned on to subject the humidifying element to sterilize filtration during only the time period when water is supplied to the humidifying element until the humidity of a room is equal to a predetermined humidity.
In order to stably generate electrolytic water, it is considered to provide a voltage varying circuit for variably controlling the voltage applied between the electrodes in the electrolytic bath to keep current constant. With respect to this type of voltage varying circuit, in a case where a circuit for adjusting the voltage only by modulating the pulse width is adopted, a radiating device (for example, heat sink) for radiating heat of the power supply circuit containing this voltage varying circuit must be designed in a large size in proportion to the amount corresponding to the voltage drop of the power supply when it is required to secure a sufficient control voltage range, and also thermal loss in the radiating device induces power consumption.